Continuity mistake: A vast majority of the movie occurs over the course of a single day, so it would be expected that Becky's hair stayed about the same. However, there were frequent fluctuations in Becky's hair's length, how her bangs were arranged, and color (whether the blue streaks could be seen at all or how much at a given time, and if she had dark roots on the top of her head).
Continuity mistake: When the 3rd platoon returns to the hideout, just as Sergeant Hwang says "Private Kim! Isn't it beautiful?", he is standing next to a tall soldier with long hair that is tied back. The shot changes to a different angle and the sergeant is now standing a foot or two ahead of the tall soldier. (00:43:31)
Continuity mistake: Kareem's mom is talking to her coworker about the fact that her son asked for James to pick him up at school. When she mentions that it's not seen as the coolest thing to date a cop, and a white one at that, her friend goes from hand low, to smoking with that hand, to drinking from the cup, in the span of a few words and a couple quick cuts. (00:09:45)
Continuity mistake: The white van headed toward the parked truck in the construction zone was about one car length away from colliding. There was a switch to an aerial view and the white van was several car lengths away from the truck. (01:06:51)
Continuity mistake: The appearance of Grace's house by the front door (to the left of the screen) changes from the time Billy is standing along the road to when he meets his mother half-way. At first, the side of the house is mostly white; it is mostly brown thereafter. The garage area to Billy's left also changes color from brown to white. (00:05:22)
Continuity mistake: A large-screen TV was on the wall opposite the staircase when Carol and Victor reached the top. Part of a small high window (above the lamp) could be seen near the top of the TV screen. When the camera shifted to the opposite side of the room, the TV temporarily transformed into a large window with floor-length drapes. (00:48:02)
Continuity mistake: The position of the dead (imposter) security guard's head over the barbell changes. When Gus says, "Jesus, he's dead", the security guard's neck is over the barbell rail, the top of his head is touching the floor, and his face is toward the front of the screen. When the camera goes to the opposite side of the dead guard, his head and neck are raised (and apparently no longer being supported by the barbell - or anything else). (00:28:28)
Continuity mistake: Near the start during the 1st bank raid, his hands change position while lying down on the ground talking to the guard.
Continuity mistake: Mikey and his friend are smoking the same inch-long joint by the back door which gets passed back and forth - no way they could keep holding/smoking it for that long given how short it was to start with. (00:04:50)
Continuity mistake: The amount/shape/size of the blood/cut on the bridge of Joey's nose varies, as does the obvious presence or absence of blood on the right side of his nose. (00:42:32 - 00:43:50)
Continuity mistake: When Driscoll is walking out to his car with his son, you see the driver's side window is rolled all the way up. When he sees Spenser and goes to talk to him, the window is now rolled down, even though he didn't do anything. (01:22:00)
Continuity mistake: In the locker room, an adjacent locker is closed then open with a yellow shirt hanging inside. Also, Ali takes a uniform jacket out of the locker Borz said she could use and holds it in front of her while they were talking. When they're almost done, Ali is turned around toward the locker and starts to remove a uniform jacket from her locker (as though this is the first time she was seeing it). (00:10:52 - 00:11:35)